"NOT VILLAINS! These are protagonists or side characters that are unlikable! (These should lean more towards characters who aren't intentionally unlikeable. Not villains, or mean girl/guys, etc.)"
1. David Chios in the Creatura series by Nely Cab. He's great in the first book, but damn he needs to get his sh*t together in the sequel. I didn't like him in that part of the story, don't know what the hell is wrong with him.
2. Tris Prior in the Divergent series by Veronica Roth. She's fine in the first book, but starting from the second book and definitely the third book she just acts supid, emotional and impulsive.
Don't have more than those two, sorry guys.